Catching Crumbling Infrastructure

In August, an eight-lane interstate bridge in Minneapolis collapsed during evening rush hour, killing 13 people and injuring 144. This collapse, and the failure to anticipate it, calls into question the adequacy of current bridge inspection methods. Why were problems with the bridge not identified? And if problems were missed in Minneapolis, could they be missed elsewhere? Could this happen again?

There is good reason to worry. Before it collapsed, the Minneapolis bridge was one of more than 70,000 bridges nationwide declared by the Department of Transportation to be structurally deficient. One in three urban bridges fall into this category.

Such bridges may be safe for travel so long as they are carefully monitored. Recent advancements in sensor technology provide the opportunity to collect detailed, real-time data on bridge performance. But this technology is being used on less than a handful of bridges nationwide. Current inspection methods, unfortunately, cannot be relied on to catch a bridge on the brink of collapse.

“We do not know which bridges should be taken out of the system, and which should be maintained,” said A. Emin Aktan, a professor of civil engineering at Drexel University and director of the Intelligent Infrastructure and Transportation Safety Institute.